And more industrial disputes are predicted to erupt over workers losing out from failing pension schemes.

A damaging power blackout was avoided after a dispute between the ESB unions and its management was resolved, while workers at Marks & Spencer were on strike over pensions last week.

And Aer Lingus is threatening legal action if Siptu goes ahead with a strike in the latest twist in the row over the €780m hole in the fund it operates jointly with Dublin Airport Authority (DAA).

There are just under 800 defined benefit pension schemes in the private sector -- these are schemes where the pension is based on the final salary and the length of service -- but half of these are in deficit, according to the Pensions Board.

This means that up to 200,000 workers, pensioners and deferred members of schemes are vulnerable to losing retirement benefits, according to Jerry Moriarty of the Irish Association of Pension Funds.

Loughlin Deegan, pensions policy adviser at business group IBEC, said the minimum funding standard was strangling company schemes.

The Pensions Board's minimum funding standard requires a scheme to have enough funds to pay out all its liabilities if it was to close immediately.

The board is the regulator for pensions.

Mr Moriarty said there would be more disputes over pensions.

He also said strict Pensions Board rules were forcing defined benefit schemes to wind up. A combination of factors, including people living longer, low interest rates and tough regulations, was making them impossible to fund, Mr Moriarty said.

"The rules are not protecting people and instead forcing schemes to wind up," he said.

"You cannot guarantee everything at every point in time. It is unrealistic to do that. There needs to be a balance between protecting pensions and allowing them to continue to pay out benefits," Mr Moriarty said.

Labour Relations Commission chief executive Kieran Mulvey backed a call from the head of the Irish Congress of Trade Unions (ICTU) David Begg for "a summit" on pensions which are sparking an increasing number of industrial disputes.

ENTITLEMENTS

Mr Begg this week said that there was a need for a national summit on the pensions crisis.

And Mr Mulvey said that we need to get unions, management, the Pensions Board and the regulator around a table to address the fact that most pension schemes in the country are in deficit.

"Workers need certainty as to their pension entitlements and whether they are getting good value for money. This is not an unreasonable request," he said.

"We need to ask whether schemes, which have been hit by poor returns in the market and the fact that people are living longer, should be forced to abide by the minimum funding standard as set by the Pension Board," he said.

This is pushing these schemes into deficit and causing increasing industrial unrest among workers, added Mr Mulvey.